The U.S. Department of Energy (DoE) has chosen to fund five projects for the development of advanced nuclear reactor designs. The reactors will be constructed by private industry. The funding is part of the Advanced Reactor Demonstration Program (ARDP) at the DOE’s Office of Nuclear Energy. The initial thirty-million-dollar fund will grow to as much as six hundred million dollars in the next seven years. Private industry is required to provide an additional twenty percent to fund the projects.
     Light-water pressurized nuclear reactors have dominated the nuclear power industry since the Atomic Age began in the 1950s. In spite of the resistance to nuclear power in the industrialized West that has developed over the past few decades, many analysts still see the need for a new generation of advanced reactors to help fight climate change.
     The goal of the DoE grants is to promote the design and construction of nuclear reactors that can be deployed in ten to fourteen years that will be more efficient, more economical, and safer to operate. This new generation of reactors will have designs that utilize more robust fuels and have passive cooling systems that will be able to prevent a reactor meltdown even if there is no power available to operate traditional active cooling systems.
      The first project being funded is the Hermes Reduced-Scale Test Reactor being developed by Kairos Power in Alameda, California. This prototype is intended to lead to the construction of commercial scale Kairos Power Fluoride Salt-Cooled High Temperature Reactor (KP-FHR). This advanced test reactor will use Tri-structural ISOtropic (TRISO) particle fuel. It will be cooled by a low-pressure fluoride salt coolant.
     TRISO fuel consists of particles that are composed of a core of uranium, carbon, and oxygen which is surrounded to by three layers of carbon and one of ceramic. This cladding is intended to prevent the release of radioactive materials from the fuel particles. The TRISO particles are the size of poppy seeds. They are gathered together into cylindrical pellets or spheres the size of billiard balls. These pellets and spheres are able to survive the extreme temperatures of gas-cooled or salt-cooled reactors.
     The second project is the Westinghouse Electric Company’s eVinci Microreactor. This is a heat pipe-cooled micro-reactor which is part of a technology demonstration scheduled to be completed by 2024. A heat pipe reactor consists of a solid block core with fuel inserted in holes in the block. Heat pipes contain a liquid that extracts heat from the core as it vaporizes. The heat is then carried to a heat exchanger for cooling and power generation. The purpose of the demonstration is to investigate the risks inherent in such a design and to decide how best to improve the manufacture and efficiency of the heat pipe system.
     The third project is the BWXT Advanced Nuclear Reactor (BANR) by BWXT Advanced Technologies in Lynchburg, Virginia. This is a transportable micro-reactor that also utilizes TRISO fuel to achieve higher concentrations of uranium. It also features an improved core design based on a silicon carbide matrix.
      The fourth project is the Holtec SMR-160 Reactor from Holtec Government Services in Camden, New Jersey. This is a small modular reactor based on light-water reactor design. Small modular reactors produce three hundred megawatts or less. They will be manufactured in factories and will be scalable by placing additional reactors at a site.
       The fifth project is the Molten Chloride Reactor Experiment by Southern Company Services, Inc. in Birmingham, Alabama. This is a twelve hundred megawatt critical fast-spectrum salt reactor design. The fuel is mixed in with the salt coolant. The nuclear reaction that takes place within the salt keeps it in a molten state. Molten salt reactors can be more efficient because they can operate at higher temperatures than conventional commercial power reactors.
     Dan Brouillette is the current U.S. Secretary of Energy. He said, “All of these projects will put the US on an accelerated timeline to domestically and globally deploy advanced nuclear reactors that will enhance safety and be affordable to construct and operate. Taking leadership in advanced technology is so important to the country’s future because nuclear energy plays such a key role in our clean energy strategy.”